Green‐Emitting Oxonitridoberyllosilicate Ba[BeSiON₂]:Eu²⁺ for Wide Gamut Displays

Abstract Light‐emitting diodes (LEDs) producing pure, highly saturated colors are the industry standard for efficient backlighting of high‐color gamut displays. Vivid color reproduction, matching the eye's perception of nature, is the central paradigm in the design of narrow‐band emitting phosphors. To cover a wide range of naturally occurring color tones, expansion of the color gamut in the green spectral region, and therefore an advanced applicable green phosphor, is highly desired. Herein, the oxonitridoberyllosilicate Ba[BeSiON₂]:Eu²⁺ showing outstanding narrow‐band green emission (λ_max ≈526 nm with FWHM ≈1600 cm⁻¹ (≈45 nm), x = 0.212, y = 0.715) when excited with InGaN‐based blue LEDs is presented. High quantum efficiency and low thermal quenching (>90% rel. quantum efficiency at 100 °C) as well as excellent scalability make the material suitable for industrial application in high color‐gamut LED displays. A prototype phosphor‐converted‐LED (pc‐LED), with green‐emitting Ba[BeSiON₂]:Eu²⁺ and K₂SiF₆:Mn⁴⁺ as red phosphor shows an extraordinary coverage in the CIE 1931 color space of 109% compared to the DCI‐P3 standard, topping the widely applied β‐SiAlON:Eu²⁺ phosphor (104%), making it suitable for use in phone displays, monitors, and television screens.